Improvement in valve-gears for steam-engines



2 Sheets-Sheet 1'.

G. H. GORLISS. Valve-Gear for Steam-Engines.

' No. 215,884. Patented May 27,1879.

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A G. H. GORLISS. Valve-Gear fo r Steam-Engines.

No. 215,884. Patented May 27,1879.

UNITED STATES .e'rnu'r OFFICE.

GEORGE H. GORLISS, OF PROVIDENCE, RHODE ISLAND.

JMPROVEMENT IN VALVE-GEARS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 215,884, dated May 27,1879; application filed February 6, 1879.

To all whom it may concern:

Be it known that I, GEORGE H. OORLISs, of Providence, in the State ofIthode Island, have made certain new and useful Improvements relating toSteam-Engines; and I do hereby declare the following to be a full andanism engages and disengages at each stroke.

I have devised an apparatus for this pur pose in which the openingmechanism is connected with the valve by means of a steel shoulder on alight lever, which is operated by means of a light detaching-rod turningon an adjustable center, a stop (which may be adjustable) carried bysaid rod causing said lever to turn to release the valve and allow it tobe closed. The steel shoulder engages with a steel catch-piece 011 thevalve-arm, holding it securely, but offering great facility forliberation by a small movement of the light lever which carries theshoulder. The lever carrying the shoulder turns on the same center asthe valve, so that there is no rolling motion of one part upon theother. The detachingmovement is effected with certainty at the propermoment, and without exerting any appreciable disturbing influence on thegovernor.

The following is a description of what I consider the bestmeans ofcarrying out the invention.

Figure 1 is an elevation of the general arrangement. 'Fig. 2 is anelevation, partly in section, illustrating the invention. Fig. 3 is aplan. Fig. 4 is a detail perspective view of one of the swivel-guidesand part of one of the steel-pointed followers.

Similar letters of reference indicate like parts in all the figures.

A description of the mechanism for operating one valve will suffice forboth.

0 is the stem or shaft of a steam-inlet valve of the circular slidingdescription invented and used by me. (Not represented.) K is an armrigidly fixed thereon.

K is a rod connected to the arm K, and having at its lower end anysuitable device for pulling the arm K in the direction to close thevalve on the shaft (J.

K is arocking lever, centered on the same valve-shaft O, and receiving apositive rocking motion through suitable connections. (Not represented.)Y

K is alight lever with steel shoulder K", turning on a pivot, K",carried on the lever K having a spring, K, which urges it toward theshaft 0. The shoulder K on the lever K, at each upward movement of leverK engages with the steel catch-piece K on the arm K and liftingthelatter opens the valve.

By releasing the catch K from the shoulder K at the desired point in thestroke, the point of closing the valve, called the point of cut-off, isdetermined.

K is a light slotted rod loosely embracing a pin, K, fixed in the upperend of the lever K and pivoted at K to another lever, K the position ofwhich latter is controlled by a governor or other means, as shown inFigs. 1, 2, and 3.

The position of the stop K in the slotted rod K determines the point inthe stroke at which its shoulder K becomes disengaged from the catch Kon the valve-arm K to allow the latter to drop and close the valve.

The slot in the slotted rod K is of sufficient length to accommodate theextreme throw of the parts in every possible adjustment.

At each oscillation of the rocking lever K the shoulder K engages thecatch K on the valve-arm K and lifting it opens the valve; but as soonas the pin K", above mentioned, meets the stop in the slotted rod Kformed by the end of the slot in the rod, the further motion of therocking lever K disen gages the valve-arm K and allows it to drop.Shifting the stop K to the right or left by the action of a governor orother means will delay or hasten the period of such dropping. There isno rolling movement of the shoulder K upon the catch K at any time, andno sliding movement except at the instant of disengagement.

A very slight force of resistance applied at the stop K is sufficient tocause the disengagement of the shoulder K from the catch K; but untilsuch force is applied the parts remain engaged without any tendency toseparate.

In Fig. 1, I have represented connections adapted for effecting theregulation by the aid of a governor. The levers K turn on fixed centers,their arms being connected to the steel-pointed followers K K the otherends of which play through the swivel-guides K and rest easily againstthe cam-shaped surfaces 2' i, which are moved up and down, as required,by a governor I as represented.

It will be understood that the descent of the governor-balls I lowersthe cam-surfaces i i, and by allowing the steelpointed followers K K tomove to the left under the influence of the coiled spring K (shown inFig. 3,) or other force, moves the center K to the right, and delays thecut-off by delaying the impact of the pin K with thestop K in rod K andliberates the valve-arm X.

By means of the rod K resting on the pin K of the light lever K, asshown, I obtain a delicatemeans of effecting the detaching movement, andcan move the other center, K, forward andbackward, either by the meansshown or by other means, to effect the changes in the point of cut-off.I esteem it particularly important, however, in connection with my camsz i, which serve as a medium for communicatingthe changes from thegovernor, which cams are made the subject of a separate application forpatent.

Modifications may be made. ism for both ends of the stroke may beoperated by any suitable mechanism controlled by the governor; or I canvary the positions of the stops K by hand adjustment, or any othermeans.

The rod K, with stop, need not be slotted. The lower half of the slottedpart may be removed, and it will still maintain the contact of the upperpart with the pin K by gravity.

It will be seen that in Fig. 1 the cam-shaped surfaces are shown asoperated by a speed governor, while in Figs. 2 and 3 provision is madefor a hand adjustment.

The mechanism herein shown and described for regulating the speed ismade the subject of a separate application.

I do not claim, broadly, a valve mechanism in which the valve is openedby a dog or shouldered lever pivoted on a rocking lever turning on thesame center as a valve; but

I claim as my invention- The rocking lever K carrying the light leverK,with the shoulder K engaging with the catch-piece K on the valve-arm Kthe whole moving on a common axis with the valve to be operated, incombination with the stop K carried by the light detaching-rod K turningon the adjustable center K and controlled substantially as hereinspecified, the whole being arranged, constructed, and operatedsubstantially as herein set forth.

In testimony whereof I have hereunto set. my hand this 1st day ofFebruary, 1879, in the presence of two subscribing witnesses.

GEO. H. CORLISS.

Witnesses:

JEssE WALRATH, GEORGE A. Donen.

The mechan-

